Cesarean section, commonly referred to as a C-section, is a surgical procedure that provides an alternative to difficult or failed vaginal delivery of a baby, and entails delivery through a surgical incision in the parturient woman's abdomen and uterus. In recent years a significant proportion of deliveries via C-section have been performed during the second or later stages of labor. Since the pregnant woman has labored for a period of time, the fetal head may be well seated in the maternal pelvis. At such a late stage, molding and caput of the baby's head occurs in an attempt to squeeze the head through the sometimes narrow and tortuous route of the maternal birth canal. The tissues of the vagina and cervix can stick to the baby's head in this very wet environment, creating an environment which places a large amount of suction on the fetal head. This environment can create significant resistance to the obstetrician's attempts at digital or manual extraction. As a result, the obstetric surgeon will often encounter a difficult and potentially traumatic disengagement of the deeply wedged fetal head during the ensuing C-section procedure.
The maneuvers to disengage the impacted fetal head (IFH) include pushing the head back up through the birth canal and into the uterus, and/or pulling the infant's feet up through the uterine incision. Both methods may cause serious maternal and neonatal complications. For example, a surgical assistant will typically place a hand into the vagina and push up on the fetal head while the surgeon attempts to gain leverage from the surgical field above. Often when the seal is broken a loud sucking sound can be heard as the head disengages from the birth canal walls. The force required to accomplish this may at times be excessive, and may lead to complications such as low neonatal Apgar scores, fetal injuries such as clavicle fracture, long-bone fractures or skull depression/fracture, fetal head laceration, tearing and extension of the uterine incision, maternal hemorrhage, injury to the maternal bladder or uterine blood vessels, and (rarely) fetal death.
A deeply impacted fetal head is estimated to occur during 1.5% of all C-section deliveries and 25% of all emergency C-sections. With less training in forceps deliveries and recent recommendations by the American College of Obstetricians and Gynecologists (ACOG) and other sources to continue pushing during the second stage of labor for up to three hours, the problem of an IFH is quickly becoming a growing problem. In addition, maternal obesity, diabetes and macrosomia continue to contribute to the incidence of IFH requiring emergency C-section.
Devices and methods have been proposed for assisting delivery via C-section when the fetal head is deeply wedged in the female pelvic cavity. For example, U.S. Pat. No. 9,055,973 and U.S. Pat. No. 8,556,913, both to Varma disclose an inflatable balloon attached to one side of a foldable plate for supporting and pushing an impacted fetal head up into the uterus. While useful, the plate can wedge itself into the vaginal sidewalls which can be damaging to the edematous tissues and cause lacerations. U.S. Pat. No. 9,408,633 to Leitch teaches a fetal head support for elevating an impacted fetal back into the uterus. The contact surface of the support includes gaps which do not contact the fetal head, such that the device applies pressure unevenly to the fetal skull. U.S. Pat. No. 9,039,714 to Barrier et al. discloses an obstetric device which expels air to break the vacuum seal between the fetal head and the birth canal walls. The device is not intended for supporting or relocating the fetal head within the birth canal.
While the above prior art devices and methods may be useful for their intended purpose, there remains a need for an improved apparatus for repositioning an impacted fetal head and guiding it back up through the birth canal and into the uterus prior to delivery by C-section. It would also be beneficial to provide a more efficient means for displacing an impacted fetal head that will minimize maternal and neonatal complications.